My Mum was into health food before the crowd. As a child in the 70s, I was the only kid in my class with brown bread sandwiches. We ate Sanitarium muesli (powdery stuff it was too). Crisps didn't darken our door. Nor did chewing-gum, but that was because my father inherited his father's aversion to it and that's a whole another story.
Anyway, the point of this is my Mother bought a yoghurt maker. It was a round, plastic contraption, in yellow and beige. I think made by Braun. From memory It acted like a thermos. You put a jam-jar in the middle, with your milk and a spoonful of seed yoghurt, covered it with the plastic cap, plugged in the machine and left it overnight. The yoghurt maker kept a constant temperature at which the friendly bacteria would multiply, and in the morning - yoghurt!
I think Mum still had it as recently as January, when the wholesale clear-out of the old family home took place, before my parents moved to the townhouse in the city.
Nowdays, there is a product calls Easy-Yo, which comes as a powder, to which you may just add water. I've never tried it, but know through experience in the kitchen here at Yoga Plus that making yogurt is easy. Here's how I've done it:
Heat a litre of milk until it reaches simmer point, and a skin forms. (we use UHT - as fresh milk is near impossible to find on Crete). Allow it to cool to slightly above blood temperature. Add a spoonful of live, natural yoghurt as a starter and whisk to combine. Cover securely and leave overnight in a clean warm, but not hot spot. We usually put it on top of the oven. The residual heat in the milk helps the friendly bacteria to do their work and thicken the milk into yoghurt.
In the morning, the thickest and creamiest part will be at the top, and some of the whey may have separated on the side. You can whisk it to combine and provide a smooth texture.
It tastes great with good honey (make sure you have real honey, and not sugar syrup with honey for flavour).
The other thing I like to do is to thicken yoghurt, greek style, by straining it through muslin. You can use an old white pillowcase, provided it is very clean (rinse first to make sure that any detergent residues have gone. Don't wash with fabric softener!) A clean teatowel works well too.
Put a kitchen sieve over a bowl, or saucepan. Line it with the cheesecloth or substitute. Pour the yoghurt into it. Cover with clingfilm and leave overnight in the fridge. The whey will drip through into the bowl, leaving thickened yoghurt the consistency of commercial sour cream. If you have time, go back after an hour or two and stir so the thicker yoghurt on the bottom of the sieve can make way for thinner yoghurt. You'll get a thicker overall product this way.
The yoghurt is great eaten for breakfast with honey, used to make yoghurt dips like tsatsiki. I'm also going to try a pie, made with semolina and thickened yoghurt to produce something quiche-like. It may work, it may not! I'll post here when I try it!
A tip : If the cheesecloth overlaps the side of the sieve/bowl, then it's good to stand the bowl/sieve in a larger tray or bowl, as the fabric can act like a wick and drip whey/water down the side into the fridge.
In the book Frenchwomen Don't Get Fat, the author recommends yoghurt every day for good health. So eat up!